GB488459A - An improved power transmission unit for vehicles of the four-wheel power transmission type - Google Patents

Abstract

488,459. Motor-vehicle driving-gear- JACKSON, L. MELLERSH-. (Marmon- Herrington Co., Inc.) Oct. 6, 1937, No. 27077. [Class 79 (ii)] Four-wheel driving-gear comprises a driving or input shaft 19, 21, a driven shaft 23 for driving one pair of wheels, means by which the said two shafts may be directly connected, a second driven shaft 34, 36 for driving another pair of wheels, and a power train between the driving shaft and the second driven shaft comprising an axially-shiftable clutching element 33, which upon over-running of the driving shaft will automatically shift to clutching position and upon over-running of the second driven shaft will shift to declutching position. In the construction shown, the shaft 23 drives the rear wheels through a propeller shaft 25 and the shaft 36 drives the front wheels. The engine 17 drives the shaft 19 through the usual change-speed gear 18. The shafts 23, 34 are coupled by a helical-toothed gear train 26, 32, 33 of which the gear 33 is slidable on its shaft 34 and carries ratchet teeth 40, 41 adapted to engage corresponding teeth on the shaft. Thus, when the gear 33 is driven in one direction, it slides axially, due to the side thrust of the helical teeth, to bring one set of ratchet teeth into action to drive the shaft, and when it is driven in the other direction it slides to bring the other set of teeth into action. Further, in whichever direction the gear 33 is driven the shaft 34 can over-run the gear to compensate for the longer path taken by the front wheels on a curve. The gear train 26, 32 forms part of an auxiliary two-speed gear, the gear 26 being adapted to be driven directly by the shaft 21 through a sliding clutch gear 28 or indirectly through the gears 28, 30, 32. The gearing is enclosed in a casing 20 secured by a bracket 50 to the frame.